Electromagnetic Scattering from a Dielectric-Coated Sphere with an Embedded Impedance Film

The electromagnetic scattering from a multilayered sphere modal solution of Wait [1] is modified to allow the inclusion of infinitesimally thin impedance films at layer boundaries. The modified solution is implemented in a computer algorithm and the scattering from an aluminum sphere coated with a dielectric Delrin(tm) layer containing an embedded impedance film is computed. This target was fabricated and laboratory measurements performed in the 2-18 GHz region are in good agreement with computations. Index Terms: Electromagnetic scattering, impedance sheets, spherical scatters.